The pumped hydro storage potential of the Great Lakes

The potential energy contained in the waters of the Great Lakes amounts to approximately six thousand terawatt hours, enough to supply the US and Canada with electricity for an entire year were the lakes to be drained to sea level. This of course will never happen, but there may be potential for partial utilization of the resource. A pumped hydro system that uses Lakes Huron and Michigan as the upper reservoir and Lake Ontario as the lower could theoretically generate 10 terawatt-hours, or more, of seasonal energy storage without changing lake levels significantly. The most likely show-stopper is the increased likelihood of flooding in the lower St. Lawrence River during pumped hydro discharge cycles. (Inset: Niagara falls runs dry in 1969).

The idea of using the Great Lakes for pumped hydro storage isn’t new – I remember reading about it once before but can no longer find the article. What brought it back to mind was a comment posted by Alex on the recent 100% renewable California thread in which he agreed that while there were indeed no fresh water lakes that no one cared about there were some that could perhaps be adapted for pumped hydro without anyone noticing: